Effect of Disorientation On Visual Analysis, Familiarity Decision and Semantic Decision On Faces

The disproportionate effect of vertical inversion on the processing of faces has often been interpreted as indicating differences in perceptive strategies between upright and inverted faces. If this is true, then the mathematical relation between the performance and the angular deviation would not be a linear function. Thirty subjects processed faces shown under 10 angular deviations from upright (0 deg) to upside-down (180 deg) in steps of 20 degrees, in a random design. Three cognitive levels (a between-subject factor) were tested, namely, gender classification of unfamiliar faces, familiarity decision on famous vs. unknown faces, and semantic decision (occupation) on famous faces, with 480 items per subject and task. We found no sign of a change of processing strategies for the upright vs. inverted presentations: a clear linear function emerged. However, the nature of the task could influence the effect of the angular deviation on the performance. Results suggest that, up to now, there is no definite proof of qualitatively different mechanisms underlying the processing of upright and inverted faces, respectively

[Presenting a battery for assessing spatial neglect. Norms and effects of age, educational level, sex, hand and laterality]

The aim of this study was to build up a battery for assessing spatial neglect, then to analyse the norms and potential effects of age, education level, sex, hand used, and laterality. It was also to contribute evaluating the pseudoneglect phenomenon described by Heilman, which consists in a tendency of normal subjects to neglect the right peripersonal space. Tasks selected were presented to important groups of normal subjects, most often larger than 450. The battery comprised of a bell cancellation test, scene copy, clock drawing, two line bisection tasks, identification of overlapping figures, text reading, writing task, and the representational task of the France map. For each of them, different variables were selected, especially investigating the difference between performance in the right and the left hemispaces. This study allowed defining the threshold values (percentiles 5 and 95) for deciding of the pathological character of a patient performance. It also showed that the pseudoneglect phenomenon is more obvious in some tasks such as line bisection, and probably also in the representational task of the France map and writing. His importance and at times his side were influenced by the factors we studied, with between tasks differences, but also by the nature of the task to be performed, and especially his verbal component

Right spatial neglect after left hemisphere stroke: qualitative and quantitative study

Objectives: Comparatively little research has been conducted on right neglect after left brain damage. The authors sought to assess contralateral neglect in subacute left hemisphere stroke patients using a comprehensive test battery validated in a large control group after right hemisphere stroke. Methods: Seventy-eight left hemisphere stroke patients were assessed. The test battery included a preliminary assessment of anosognosia and visual extinction, a clinical assessment of gaze orientation and personal neglect, and paper-and-pencil tests of spatial neglect in the peripersonal space. Only nonverbal tests were used. Results: Drawing and cancellation tasks revealed neglect in 10 to 13% of patients. The combined battery was more sensitive than any single test alone. A total of 43.5% of patients showed some degree of neglect on at least one measure. Anatomic analyses showed that neglect was more common and severe when the posterior association cortex was damaged. Conclusions: The frequency of occurrence of right neglect was, as expected, much lower than that reported in a study using the same assessment battery in right brain damage stroke patients. Nevertheless, neglect was found in a substantial proportion of patients at a subacute stage, suggesting that it should be considered in the rehabilitation planning of left brain damage stroke patients

Sensitivity of clinical and behavioural tests of spatial neglect after right hemisphere stroke

The lack of agreement regarding assessment methods is responsible for the variability in the reported rate of occurrence of spatial neglect after stroke. The aim of this study was to assess the sensitivity of different tests of neglect after right hemisphere stroke